Grinding and lapping machine



Aug 16, 1938. H. w. DUNBAR 2,127,210

GRINDING AND LAPPING MAGH INE Filed July 31, 1937 4 Sheets-Sheet lHaw/am] WEUNBHR Aug. 16, 1938. H. w. DUNBAR 2,127,210

GRINDING AND LAPPING' MACHINE Filed July 31, 1957 4'Sheets-Sheet 2 4 AAA Gum ,1

Aug. 16, 1938. H. w. DUNBAR GRINDING AND LAPPING MACHINE Filed July 31,1937 4 Sheets- Sheet 3 Ha WFIRD W. DUNEHR Patented Aug. 16, 1938 IUNITED STATES PATENT OFFICE GRINDING AND LAPPING MACHINE Howard W.Dunbar, Worcester, Mass., assignor to Norton Company, Worcester, Mass.,a. corporation of Massachusetts Application July 31, 1937, Serial No.156,168

16 (Jlaims. (Cl. 51-95) This invention relates to grinding and lappingFigure 4 is a plan view, on an enlarged scale, machines and moreparticularly to a machine for of the lapping wheel slide having a coverremoved successively grinding and lapping of cylindrical to show thewheel spindle reciprocating mechwork pieces. anism and the gear box cutaway and shown in One object of this invention is to provide a sectionto more fully show the lapping wheel 5 simple thoroughly practicalcylindrical grinddriving mechanism; and ing and lapping machine..Another object is to Figure 5 is a sectional view taken approxi-Drovide an improved abrading machine for finmately on the line 5-5 of Fgure ishing cylindrical work pieces by first grinding The improvedcombined cylindrical grinding 1 the work piece and then lapping it tothe desired and lapping machine has been illustrated in the size andfinish without removing it from the madrawings comprising a base IIIwhich supports a ch ne. A further object is to provide acylongitudinally reciprocable work table II on a V- lindrical grindingand lapping machine in which way l2 and a flat way 13 formed on the baseIII.

a rotatable grinding wheel and a rotatable lap- The longitudinallymovable work table II is proping wheel are successively fed intooperative vided with a. rotatable work support comprising 1 engagementwith the work to first grind and a headstock l4 and a rootstock-l5 whichare then lap the same. Another object is to provide provided with aheadstock center I 6 and a foota rotatable grinding wheel and arotatable lapstock center ll respectively to rotatably support pingwheel on opposite sides of a work piece, each a cylindrical work pieceI8 thereon.

30 of which is mounted on opposite ends of a carl riage which is movedto successively present the Work mtatmg mechanism grinding and lappingwheels to grind and then The headstock pp s a ot t b e dlap t work Afurther obje t, f this invenstock spindle l9 which carries a drivingplate 20 tion is to provide a feeding mechanism for sucat its Thedriving Plate face Plate cessively feeding a rotatable grinding wheeland N 15 Provided With a driving D 2| W ich s 25 a rotatable lappingwheel to grind and then lap "ranged to engage e t er a projection on thea work piece. A further object is to provide a Work Piece a Work drivingdeg ped therehydraulic operated feeding mechanism to feed The headstockand rootstock 5 are prefthe wheels rapidly when out of contact with theerably on the k ta le II to facilitate sunwork and a feed regulator toproduce a slow uni- Porting 811d lfltating Werk P eces of a desired 30form feed during the grinding and lapping operlengthti The headstockspindle l9 may be driven by any oth objects will be in part obvious orin part suitable means, such asJor example,asillustrated pointed out hrein fter. an electric motor 25 mounted on top of the head- 5 Theinvention accordingly consists in the teastock frame- The meter 15 is pd with an tures of construction, combination of elements, armature Shaft25 which ca ies a driving pulley and arrangements of parts as well asexemplified The driving P y is p e er b y of a in the structure to behereiniter described and multiple V-grooved type whichis connected bythe scope of the application of which will be a multiple V-belt 28 witha grooved pulley 29 40 indicated in the following claims. mounted on theouter end of the headstock 40 shIn the accgmpanying driabwings, in whichis spindle |9 1 Own one 0 Various 18 emmments of To facilitatesuccessively grinding and then eg fffi ii l gl fitiie zii ti fimbmdlapping piece without of same from the machine, it is desirable toprovide cylindncal gnndmg and lappmg machine a work driving mechanismwhich is of a variable bod in this invention;

Figufe 2 is a vertical sectional view, on an enspeed type so that thework may be first rotated 'lar ed scale,-taken a roximatel on the lineat a desired and predetermined speed a z z of Figure 1, r gm wheel andgrinding operation and then readily changed to slide and lapping wheeland slide in elevation a FY0991 speed for lapping operationthe and thelower parts of the machine in sections; prefe red form, the electricmotor {5 is of a vari- Figure 3 is a cross-sectional view taken aplSpeed tim which mayb Started d S p proximately on the line 3-3 of Figure2 showing y means of a push button 30 and the spe of the work supportingtable and the reciprocatwhich may be readily controlled by a rheostating mechanism therefor; 3|. The push button It and rheostat 3| have 55 Ifor grinding and lapping 'a relatively long piece' been illustrated asbeing mounted on the headstock of the machine.

Manual table traverse The work table ii is arranged so that it may bemoved longitudinally to position a work piece relative to the wheels bymeans of a manually operable traverse mechanism, such as, is old andwell-known in the art. A manually operable traverse wheel 32, is mountedon the Table reciprocating mechanism The improved machine is arranged sothat it may be utilized either for a traverse grinding and lappingoperation or for a plunge-cut operation in which a wide face wheel of awidth substantially equal to or slightly greater than the length of theportion of the work to be ground and lapped. In a plunge-cut operation,the work table II is positioned manually to locate the work piece in thedesired relation with the wheel or wheels but remains stationary duringthe grinding and lapping operations.

In a traverse grinding and lapping operation of cylindrical work, it isdesirable to provide a table reciprocating mechanism for automaticallyreciprocating the table during the grinding and lapping operations. Inthe preferred form a fluid pressure operated table reciprocatingmechanism is provided which for the sake of simplicity of illustrationis substantially identical with that disclosed in the prior UnitedStates Patent No. 2,071,677 to W. H. Wood dated February 23, 1937 towhich reference may be had for details of disclosure not found herein.

A fluid pressure cylinder 44 is supported at its opposite ends bybrackets 4i and 42 respectively which are fixed to and depend from theunderside of table II. A piston 43 is slidably mounted within thecylinder 44 and is connected by a double end piston rod 44' whichextends in oppo-' site directions from the piston 43 and passes throughthe end caps or cylinder head at opposite ends of the cylinder and isfastened to brackets 45 which are fixed to andlocated at opposite endsof the base II respectively.

Fluid under pressure is pumped from a reservoir 40 within the base II bymeans of a motor driven fluid pump 41 which draws fluid through a pipe40 and forces fluid under pressure through a pipe 49 to a control valveunit ll mounted within the base Id. The control valve unit comprises areversing valve II and a speed control or throttle valve 52 which areidentical with that shown in the U. 8. Patent No. 2,071,677 abovereferred to and to which reference may be had for further details ofdisclosure.-

The reversing valve II is controlled by a pivotally mounted reversinglever I! supported on a stud 86 on the base II. The reversing lever 55is provided with an inwardly projecting pin 5 which is arranged in thepath of adjustable table dogs 58 and 59 respectively which are arrangedto actuate the reversing lever II and to thereby 'der 40.

reverse the direction of movement of the table II as desired.

"The reversing lever 55 is provided with an adjustably mounted arrowpoint 60 at its lower end which is arranged to engage a spring pressedarrow pointed plunger 6! contained within the casing 62. The reversingvalve 5| is connected I as in the United States Patent No. 2,071,677 sothat when the reversing lever 55 is moved by the dog 58 or the dog 59,the movement of the dog and table serves to shift the reversing valve tocut-off the flow of fluid to one of the cylinder chambers and fluidunder pressure passing through the reversing valveserves to complete thereversal of the valve so as to change the direction of flow of fluid toand from the cylin- Fluid under pressure passing through the valve 50passes either through a pipe 63 or a pipe 64 into a cylinder chamber 65or a cylinder chamber '66 respectively. In the preferred form, thepiston rod 44 is hollow and fluidpassing through the pipes 63 and 64,passes through the hollow piston rod 44 to the cylinder chambers 65 and66 respectively. For further details of "construction' of the fluidpressure table actuated mechanism reference may be had to the abovementioned United States patent.

A pressure relief valve 61 isconnected with the pipe 49 by a pipe 68(Fig. 3). The relief valve 6'! is preferably of the common well-knownadjustable type which may be adjusted so that if the pressure within thefluid system exceeds a predetermined pressure, the valve opens andreturns the excess fluid pressure into the reser-- voir 48.

Grinding and lapping wheels ing or abrasive wheel to a lapping speed. Ithas been found, however, that better results may be obtained both in thegrinding operation and the lapping operation if separate abrasive wheelof the proper grit size and hardness is utilized for each operation.Therefore, to,attain the main object of this invention, it is desirableto provide two independently adjusted and controlled wheel slides,namely a grinding wheel slide and a lapping wheel slidewhich arepreferably arranged so that they may be moved successively intooperative engagement with the work piece.

In the preferred form, two independent rotatably mounted abrasivewheels, one being utilized as a grinding wheel and rotated at a normalgrinding speed, and the other being utilized as a lapping wheel androtated at a speed below the normal grinding speed which is suitable fora lapping operation, are so mounted that they may be moved successivelyinto operative contact with the work piece to first grind the same andthen to lap the surface to the desired finish and size.

In the preferred form the grinding wheel and and a flat way 12 and isarranged to move transversely relative to the work table II. Thecarriage 18 extends through an aperture 13 in the base I8 beneath thework table ways I2 and I3 and extends transversely on either side of thework table II.

Grinding wheel slide A grinding wheel slide 14 carrying a rotatablegrinding wheel 15 on a rotatable wheel spindle 16 is supported on aV-way 11 and a flat way 18 formed on the carriage 18. The grinding wheel15 may be driven by a suitable driving mechanism, such as, an electricmotor 88 mounted on top of the wheel slide 14. The motor 88 carries adriving pulley 8| which is preferably of the multiple V-groove type. Thepulley 8| is connected by a multiple V-belt 82 with a multiple V-groovepulley 83 mounted on the wheel spindle 16. The motor 88 may becontrolled by a push button 84 mounted on the wheel base I8 and whichserves to start and stop the grinding wheel motor 88 and to rotate thesame at a normal speed for grinding operationn The wheel slide 14 ispreferably arranged so that it may be adjusted longitudinally on therotatably mounted feed screw 9|. The feed screw 9| is rotatablyjournaled in bearings within the carriage 18 and meshes with a half nut92' depending from the wheel slide 14. A stop pawl 93 is pivotallymounted on a stud 94 on the transversely movable carriage .18 and isarranged to engage an abutment carried by a micrometer adjustingmechanism 95, to facilitate accurately adjusting the position of thegrinding wheel in setting of the machine for a'given operation or to beutilized to compensate for wheel wear.

Lapping wheel slide A lapping wheel slide I88 is arranged to support arotatable lapping wheel I8I which is supported on a wheel spindle I82,journaled within the slide I88. The lapping wheel slide I88 is arrangedto be adjusted transversely relative to the work piece I8 on a V-way I83and a flat way I84 formed on the transversely movable carriage 18.

The lapping wheel slide I88 is provided with a suitable drivingmechanism which permits rotating the lapping wheel at a slow speedsuitable for a lapping operation or which permits the wheel to berotated at a relatively fast speed during a wheel truing operation. Anelectric motor I85 is mounted on top of the lapping wheel slide I88. Themotor I85 is controlled by a push button I86 which permits the stoppingand starting of the lapping wheel motor from the operators controlstation.

The electric motor I85 drives a gear mechanism contained within a casingI81 which in turn rotates a multiple V-grooved pulley I88 and thegrooved pulley I88 is connected by a multiple V- belt I89 with amultiple groove pulley II 8 supported on the end of the wheel spindleI82.

The motor I85 is provided with an armature shaft 3 which rotatablysupports a gear H4. The gear 4 meshes with a gear II5 mounted on the endof a shaft 6. The shaft H6 is pro vided with a worm II1 meshing withanworm gear II8 on a vertically arranged shaft H9. The shaft H9 isprovided with a worm I28 which meshes with a worm gear |2I rotatablysupported on a shaft I22. The shaft I22 in turn supports the drivingpulley I88. By utilizing the gear mechanism above described a very slowmotion is transmitted from the motor shaft II3 to the driving pulley I88and through the belt I89 and pulley II8 rotates the lapping wheelspindle I 82 and the lapping wheel I8I at a slow rate of speed for alapping operation. The shaft I22 has an enlarged end portion I23 whichis cut out on its end to serve as a bearing support for the outer end ofthe armature shaft I I3.

In order to true the lapping wheel I8I, it is necessary to rotate it ata relatively fast rate of speed during the truing operation. Tofacilitate readily changing the speed of the lapping wheel I8I from aslow lapping speed to a fast truing speed, a manually operable clutchmechanism is provided. The end of the shaft I22 is provided with aclutch member I24 which is arranged to be engaged by a slidably mountedclutch member I25. A clutch member I25 is keyed to the armature shaft H3and is arranged to be thrown into engagement with the clutch member I23or to be thrown into engagement with a clutch member I28 formed integralwith the gear II4. A slidably mounted clutch shifting member I21 issupported on a guide rod I28 and is provided with a yoked member havingpins I29 arranged to ride in a groove I38 in the clutch member I25. Amanually operable clutch lever I3I is pivotally mounted on a stud I32and is arranged through a yoked member formed on its inner end whichengages a pin on the clutch shifting member I21 so that when the leverI3I is moved in either direction, the clutch member I25 is shifted intoengagement either with the clutch member I23 so that the armature shaftII3 drives directly to the shaft I22 to rotate the wheel spindle I82 andthe lapping wheel I8| at a relatively fast speed suitable for a truingoperation, or maybe thrown into enga'gemert with the clutch teeth I26which serves to transmit power from the armature shaft II3 through thegear reduction unit comprising the gear II4, the gear II5, the shaftII'B, the worm II1, the worm gear II8, the shaft 9, the worm I28, theworm gear I2I. to rotate the shaft I22 at a slow rate of speed which inturn rotates the wheel spindle I82 and the lapping wheel I8I at arelatively slow speed suitable for a lapping operation.

In order to stop the rotation of the reduction gear unit when thearmature shaft H3 is connected directly with the driven shaft I22 for atruing operation, a clutch member I35 is slidably keyed to the shaft I22and is arranged to be thrown out of engagement with clutch teeth I36formed on the side face of worm gear I2I.

The clutch shifting member I21 is provided with a second yoked memberI31 having pins I38 which ride in a groove I39 in the clutch member I35so that the clutch member I35 is moved simultaneously with the clutchmember I25. When the clutch shifting member I21 is moved downwardly(Figure 4) to throw the clutch member I25 into engagement with theclutch teeth I28, the clutch member I35 is moved simultaneously in adownward direction to engage with the clutch teeth I36 carried by theworm gear I2I to lock the worm gear I2i, to the shaft I22 so as torotate shaft I22 at a slow rate of speed.

Similarly when the clutch shifting member I21 is moved in an upwarddirection (Figure 4), the

clutch member I25 is thrown out of engagement with the clutch teeth I26and the clutch member I is thrown out of engagement with the clutchteeth I36 thereby rendering the reduction gear unit inoperative.Continued movement of the clutch shifting member I2'l in an upwarddirection causes the clutch member I25 to be thrown into engagement withthe clutch teeth I24 to connect the armature shaft I I3 directly to thedriven shaft I22. It will be readily apparent from the foregoingdisclosure that by manipulation of the manually operable control leverI3I, the motor I 05 may be connected to rotate the lapping wheel spindleI02 and the lapping wheel IOI at a very slow speed for a lappingoperation or may be readily shiftedv to rotate the wheel IOI at arelatively fast speed for a wheel truing operation.

Lapping wheel reciprocation In a lapping operation, it may be desirableto provide an oscillating or reciprocating movement .of the lappingwheel I 0| when used in a plunge cut grinding operation to produce thedesired break-up action between the lapping wheel and the surface of thework piece I 8. This oscillation may also be utilized in a traversegrinding and lapping operation to supplement the relative traversingmovement between the lapping wheel and the work piece. As illustrated inthe drawing this mechanism may comprise a worm I which is mounted anddriven by the lapping wheel spindle I 02. The worm I50 meshes with aworm gear I5I carried by a vertical shaft (not shown), a crank plate I52is mounted on the upper end of the shaft carrying the Worm gear I5I andis connected by a connecting rod I53 with a stud I54 carried on the endof a rock arm I55 which is pivotally mounted on a stud I56 on the wheelslide frame. The lever I55 is connected by stud I5'I with a groove I58formed between sleeve fixed on the wheel spindle and the end of the wormI 50, so as to transmit the motion of the crank I52 through the rock armI 55 to oscillate the wheel spindle I 02 as it rotates. A manuallyoperable lever I59 serves to swing the lever I 55 and to lock it againstoscillation, and serves to readily start and stop the oscillation orreciprocation of the lapping wheel spindle as desired.

The lapping wheel slide I00 is provided with a manual adjustment foradjusting it longitudinally on the carriage 10. A feed wheel I60 of thewell- 1 known grinding wheel feeding mechanism type such as is shown inthe above mentioned expired United States Patent No. 762,838. The feedw'heel I60 is mounted on a rotatable shaft I6I which is rotatablysupported in bearings (not shown) in the carriage I0. A bevel gear I 62is' mounted on the inner. end of the shaft I6I and meshes with a bevelgear I63 mounted on one end oi. arotatable feed screw I64. The feedscrew I64 is journaled in suitable bearings in the carriage I0 and isarranged to engage and mesh with a depending half nut I65 fixed to theunderside of the lapping wheel slide I00. A stop pawl I66 is pivotallymounted on a stud I61 is arranged in the path of an abutment (not shown)carried by a micrometer feed adjustment I68. By manipulation of the feedwheel I60, the lapping wheel IOI and its supporting wheel slide I00 maybe readily adjusted relative to the transversely movable carriage 10 insetting up the machine for a given operation and may also be utilized tocompensate for wear of the lapping wheel.

Grinding and lapping feed The carriage 10 is provided with a feedingmechanism which is arranged so that by movement of a control lever thegrinding wheel slide I4 and grinding wheel 15 may be moved rapidlytoward the work piece and then fed at a slow rate of infeed during thegrinding operation after which the manipulation of the control leveroperates to feed the slide 10 in the reverse direction to move thegrinding wheel slide I4 and grinding I5 away from the work piece at arapid rate and at the same time advance the lapping wheel IM and itssupporting wheel slide I00 rapidly toward the work piece. The rapidapproaching movement of the lapping wheel IOI continues until it isabout to engage the work after which the infeed is reduced to a slowuniform infeed for a lapping operation. This mechanism may be operatedautomatically to grind for a definite time interval and to thenautomatically reverse to lap the work piece. As shown in the drawings,however, a manually controlled feeding mechanism is provided of thehydraulic type comprising a cylinder I which is fixed within the baseIII of the machine. A piston I BI is slidably mounted within thecylinder I80 and is connected by a'. piston rod I82 with a bracket I83which is either fixed to or formed integral with the carriage 10.

As shown in the drawings an independent fluid pressure system isprovided for moving the work table II and for moving the carriage I0.

A reservoir I84 is provided within the base I0 of the machine. A motordriven pump I85 draws fluid through a pipe I86 from the reservoir I84and forces fluid under pressure through a pipe I81 to a control valveI88. The control valve I88 is preferably a piston type valve comprisinga valve stem I89 having a plurality of valve pistons formed integrallytherewith which form valve chambers I90, I9I and I92. In the position ofthe parts as illustrated in Figure 2, fluid under pressure passingthrough the pipe I81 enters the valve chamber I9I and passes through apassage I93 into a cylinder-chamber I94 to cause the piston I8I to movetoward the left (Figure 2).

During this movement of the piston, fluid within a cylinder chamber I95is forced out through a passage I96 into the valve chamber I92 andthrough a pipe I91 which exhausts into the reservoir I84. I

The valve stem I89 is preferably arranged so that it may be manuallyoperated from the operators control station. A manually operated controllever 200 is mounted on the outer end of a rotatable shaft 20I which isrotatably supported in suitable bearings in the base I0 of the machine.The inner end of the shaft 20I is provided with a yoke member 202 havingpins 203 which ride within a groove 204 in a spool-shaped member 205mounted on the end of the valve stem I89. The lever and valve as shownin Figures l and 2 are in position to start an infeeding movement of thegrinding wheel. After the grinding operation is completed the controllever 200 is rocked in a counter-clockwise direction (Figurev 1) whichserves to shift the valve stem I89 toward the right (Figure 2) toreverse the flow of fluid to the cylinder I80. When the valve is shiftedtoward the right, fluid under pressure passing from the pipe I81 intothe valve chamber I9I passes through the passage I96 into the cylinderchamber I95 to cause the piston I8I and the carriage I0 to move towardthe right (Figure 2) to cause the grinding wheel 'I5to rapidly move awayfrom the surface of the work being ground and at the same time causes,the lapping wheel I8I to rapidly approach the work piece for a lappingoperation.

A pressure relief valve 288 is provided in the pipe line I81 and servesin case the pressurein the pipe line exceeds a predetermined pressure toallow the excess fluid under pressure to exhaust through a pipe 281 tothe reservoir I84.

While in the drawings two independent fluid pressure systems have beenillustrated for simplicity of illustration, a single reservoir may beemployed and a motor driven double geared pump unit may be substitutedfor the pumps 81 and I85 which may be driven from a single pump drivemotor.

In the mechanism abovedescribed, namely, the cylinder I88 and piston I8Ias controlled by the manually operable control lever 288 and the valveI88 serves to cause a rapid movement of the wheel carriage III in eitherdirection. In order to grind the work and then lap the work, it isdesirable to provide a feed regulator which as illustrated comprises ahydraulic feed regulator such as a dash pot piston and cylinder. A dashpot piston and cylinder of the type shown and described in the UnitedStates Patent No. 2,023,704 to H. A. Silven dated December 10, 1935 hasbeen illustrated in the present case. Reference may be had to this priorpatent for a detailed disclosure of the construction and operation ofthis mechanism. A dash pot cylinder 2I8 is mounted on the right-handcylinder head so that the dash pot piston 2 is slidably mounted thereinand is also slidably mounted on the piston rod I82. The dash pot piston2 is normally held in a position toward the right by means of a spring2I2. When fluid and the pressure is admitted to the cylinder chamber I84to cause a rapid approaching movement of the grinding wheel I5, thisrapid approaching movement continues until an adjustable sleeve 2l8carried by the piston rod I82 engages the end of the dash pot piston 2|I. The rapid approaching movement of the grinding wheel I5 is thereafterreduced to a slow uniform grinding feed by resistance encountered inexhausting oil from the dash pot cylinder through an adjustable needlevalve so that the desired grinding feed may be readily obtained. Theinfeeding movement of the grinding wheel continues until an adjustablestop sleeve! engages the end surface of the dash pot cylinder head tothereby positively limit the approaching feed of the slide 14 and thegrinding wheel 15.

A similar hydraulic feed regulator is mounted on the left-hand cylinderhead to slow down the rapid approaching movement of the lapping wheelIIII to a desired slow speed as-the lapping wheel approaches the workpiece I8. This mechanism comprises a dash pot cylinder 2I5 fixedlymounted to the left-hand cylinder head (Figure 2). A dash pot piston 2I6is slidably mounted within the dash pot cylinder 2I5 and is alsoslidably mounted on the piston rod I82.. A spring 2II serves to normallyhold the dash pot piston 2I6 in its end position toward the left (Figure2). The rapid approaching movement of the lapping wheel I8I continuesuntil an adjustable sleeve 2I8 mounted on the piston rod I82 engages theend face ofthe dash pot piston 2I6.. Continued approaching movement isthereby reduced to a slow feeding movement due to the fact that thefluid within the dash pot chamber must exhaust through an adjustableneedle valve, thereby retarding the rapid movement caused by the pistonI8I to produce a slow feed of the lapping wheel "I. The lapping wheelapproaches the work piece I8 until a positive stop sleeve 2|! which isadiustably flxed on the sleeve 2" engages the end face of the dash potcylinder head to positively limit the movement of the wheel carriage I8toward the right (Fig. 2).

If desired in operation of this machine, the hydraulic feed regulator oneither end of the cylinder I88 may be rendered ineifective by adjustmentof the sleeves 2I8 and 2I8 and the adjustable stops 2 and 2I8,respectively. If desired the grinding wheel maybe caused to rapidlyapproach the work piece until the positive stop 2 engages the end of thecylinder head and similarly the lapping wheel may be caused to rapidlyapproach the surface of the work piece I8 until the adjustable stop 2I9engages the end of the dash pot cylinder 2I5. This operation involvingmerely adjustments of the respective parts so that-the adjustable stopengages the end of the. cylinder head prior to the stop sleeve engagingthe end of the dash pot piston.

It will be readily apparent from the foregoing disclosure that thegrinding and lapping wheel carriage I8 may be readily caused to move ineither direction to first position the grinding wheel II in operativecontact with the work piece for either a plunge cut or a traversegrinding operation and thereafter by shifting the control lever 288 in acounter-clockwise direction (Figure 1) first to cause the grinding wheelI5 and its supporting slide II to move away from the work piece, and thelapping wheel IN. and its supporting slide I88 to move rapidly into anoperating position in engagement with the work piece I8 to lap the same.

The operation of this machine will be readily apparent from theforegoing disclosure. A work piece I8 to be ground and lapped is mountedon the work supporting centers I8 and I1 between the rootstock I4 andI8. The work piece is then set in rotation by the push button 88 and thespeed of the work adjusted by means of a rheostat 8i to cause the workto rotate first at a grinding speed. If. as shown in the drawings, apiece of work is to be ground requiring a traverse grinding operation.the work table II is then set in motion by manipulation of the controlvalve 82 and the reverse control lever 58. The lever 288 is then movedinto the position as shown in Figure 1 to cause. the wheel carriage I8to be moved toward the left, Figures 1 and 2, to move the grinding wheelI8 toward the work piece. for

a cylindrical grinding operation thereon. The grinding operation iscontinued until the work piece I8 has been ground to the desired extent,after which the control lever 288 is shifted in a counter-clockwisedirection to reverse the positionof the control valve I88 and therebycause the wheel carriage I8 to move toward the right (Figures 1 and 2)to rapidly move the grinding wheel I5 away from the work and to cause arapid approaching movement of the lapping wheel I8I. During thismovement the rheostat 88 may be adjusted to change the speed of the workto a proper speed for a lapping operation. The lapping operation maythen proceed to the desired extent after which. the control lever 288may be moved into a grinding position to separate the lapping wheel IIIIfrom the work, after which it may be moved into a central or neutralposition to stop the movement of the wheel carriage during removal ofthe finish ground and lapped piece of work. If it is desired tooscillate the lapping wheel l0! during the lapping operation, the leverI59 may be actuated to start the oscillation of the lapping wheelspindle. If desired, the hydraulic feed mechanism for the grinding wheelcarriage may be utilized merely as a positioning movement, in which casethe adjustable stops 2 and M9, respectively, are adjusted to stop therapid approaching movement either when or just before the grinding wheel15 and the lapping wheel l0l engage the work piece l8, after which themanually operable feed wheels 81 and I60 may be utilized to produce thedesired infeeding movement during the grinding, and later, during thelapping operation.

It will thus be seen that there has been provided by this inventionapparatus in which the various objects herein above set forth, togetherwith many thoroughly practical advantages, are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter herein before set forth, is to be interpretedas illustrative and not in a limiting sense.

I claim:

1-...A grinding and lapping machine having a base, a longitudinalLvmovable work supporting table, a rotatable work support thereon, meansto rotate said work support at either a grinding or a lapping speed, atransversely movable carriage, a rotatable grinding wheel thereon, meansto rotate said wheel at a normal grinding speed, arotatable lappingwheel on said carriage, means to rotate said lapping wheel at arelatively slow lapping speed and a carriage 'ieeding mechanism to movesaid carriage transversely in either direction successively to move thegrinding wheel and; the lapping wheel into operative engagement with thework successively to grind and lap the 2. A grinding and lapping machinehaving a base, a longitudinally reciprocable table thereon, a rotatablework support on said table, means to rotate saidsupport at either agrinding or a lapping speed, a transversely movable carriage on saidbase, a rotatable grinding wheel adjustably mounted on said carriage,means to rotate said wheel at a normal grinding speed, a rotatablelapping wheel adjustably mounted on said carriage, means to rotate saidlapping wheel either at a relatively slow lapping speed or at arelatively fast speed for a truing operation, and a carriage feedingmechanism operative to move said carriage transversely in eitherdirection to successively move the grinding wheel and the lapping wheelinto operative engagement with the work to grind and lap the same.

3. A grinding and lapping machine having a rotatable work supportthereon, means to rotate said work support at either a grinding or alapping speed, a transversely movable carriage, a rotatable grindingwheel thereon, means to rotate said grinding wheel at a normal grindingspeed, a rotatable lapping wheel on said carriage, means to rotate saidlapping wheel at'a relatively slow lapping speed, said grinding andlapping wheels being arranged successively to engage opposite sides ofthe work piece, and a carriage feeding mechanism to move said carriagetransversely in either direction successively to move the grinding wheeland the lapping wheel into operative engagement with the work to grindand lap the same.

4. A grinding and lapping machine having a base, a rotatable worksupport thereon, means to rotate said work support at either a grindingor a lapping speed, a transversely movable carriage on said base, arotatable grinding wheel. thereon, means to rotate said wheel at anormal grinding speed, a rotatable lapping wheel on said c'arriage,means independently to rotate said wheel at a relatively slow lappingspeed, a carriage feeding mechanism including a fluid pressure operatedpiston and cylinder operatively connected to move said carriagetransversely in either direction to successively move the grinding wheeland lapping wheel into operative engagement with the work tosuccessively grind and lap the same. a

4 means to rotate said wheel at a relatively slow lapping speed, acarriage feeding mechanism comprising a fluid pressure operated pistonand cylinder operatively connected to move said carriage transversely ineither direction, and means including a hydraulic feed regulator tocontrol the grinding and lapping feed and to control the final positionsof said grinding and lapping wheels.

6. A grinding machine having a base, a longitudinally reciprocable tablethereon, a rotatable work support on said table, a transversely movablecarriage, a rotatable grinding wheel adjustably mounted on saidcarriage, means to rotat said grinding wheel at a normal grinding speed,a rotatable lapping wheel adjustably mounted on the carriage, means torotate said lapping wheel at a relatively slow lapping speed, saidgrinding and lapping wheels being arranged to be moved successively intoengagement with said work piece, a carriage feeding mechanism includinga fluid pressure operated piston and cylinder interposed between thecarriage and base, means including a, manually operable valve to controlthe admission of fluid under pressure to said cylinder to move thecarriage transversely in either direction so as to successively move thegrinding and lapping wheels into operative engagement to sucand a secondadjustable stop which is arranged to limit the infeeding movement ofsaid lapping wheel when the carriage is moved in the opposite direction.

7. A grinding machine having a base, a longitudinally reciprocable worktable, a rotatable work support thereon, means to rotate said worksuccessively engage said work piece to first grind and then lap saidwork piece, a carriage feeding mechanism therefor including a fluidpressure operated piston and cylinder operatively connected to move saidcarriage, a manually operable control valve to control the admission offluid to said cylinder and cause said carriage to move in eitherdirection, a feed regulator to arrange to modify the carriage movementas the grinding wheel engages the work, to produce a grinding feed, anda second feed regulator which is operative when said carriage moves inthe opposite direction to regulate the infeeding movement of saidlapping wheel.

8. A grinding and lapping machine having a longitudinally reciprocabletable thereon, a rotatable work support on said table, a transverselymovable carriage on said base, a rotatable grinding wheel adjustablymounted on said carriage, means to rotate said wheel at a normalgrinding speed, a rotatablelapping wheel adjustably mounted on saidcarriage, means to rotate said lapping wheel at. a relatively slowlapping speed, said grinding and lapping wheels being arrangedsuccessively to engage the work piece on diametrically opposite sides, acarriage feeding mechanism therefor, including a fluid .pressureoperated piston and cylinder, a manually operable control valve thereforto cause a rapid approaching movement of the carriage in eitherdirection, a hydraulic feed regulator arranged to reduce the rapidapproaching movement to a slow grinding feed when the grinding wheel ismoved into operative engagement with the work piece, and a secondhydraulic feed regulator which is arranged to reduce the rapidapproaching feed to a relatively slow infeeding movement of the lappingwheel as the lapping wheel is moved into operative engagement with thework piece.

9. A grinding machine having a longitudinally movable, rotatable worksupport, a transversely movable carriage, a wheel slide movablelongitudinally on said carriage, means to .adjust said slidelongitudinally on said carriage, a rotatable grinding wheel supportedthereon, a lapping wheel slide adjustable longitudinally on saidcarriage, means to adjust said lapping wheel slide longitudinally onsaid carriage, a rotatable lapping wheel supported thereon, saidgrinding and lapping wheels and slides being arranged to successivelyengage a work piece on opposite sides thereof, a carriage feedingmechanism therefor including a fluid pressure operated piston andcylinder operatively connected to move said car-- riage rapidly ineither direction, a hydraulic wheel feed regulator associated with saidcylin-- der and arranged to reduce the rapid approaching movement to arelatively slow grinding feed as the grinding wheel approaches the workpiece, and a second hydraulic feed regulator associated with said pistonand cylinder and arranged to slow down the rapid approaching movement ofthe lapping wheel when it moves into en'gag e ment with the work piece.5

10. A' grinding machine having a longitudinally movable, rotatable worksupport, a transversely movable carriage, a rotatable grinding wheeladjustably mounted thereon, a rotatable lapping wheel adjustably mountedon said carriage, said grinding and lapping wheels being arranged tosuccessively engage the work piece on diametrically opposite sidesthereof, and a, carriage feeding mechanism therefor including a fluidpressure operated piston and cylinder operatively connected to move saidcarriage rapidly in either direction, a manually operable controlvalve'to cause a rapid movement of the carriage in either direction, ahydraulic feed regulator which is arranged to reduce the rapidapproaching movement to a relatively slow grinding feed when thegrinding wheel approaches and engages the work piece, and a secondhydraulic feed regulator which is arranged to reduce the rapidapproaching movement to a slow infeeding movement when the carriagemoves in the opposite direction as the lapping wheel engages the workpiece.

11.- A grinding machine having a longitudinally movable, rotatable work.support, transversely movable carriage, a rotatable grinding wheeladjustably mounted on this carriage, a rotatable lapping wheeladjustably mounted on said carriage, said grinding and lapping wheelsbeing arranged to successively engage opposlt sides of a work piece, anda carriage feeding mechanism therefor, including a fluid pressure pistonand cylinder to move said carriage transversely in either direction, amanually operable control valve to control the admission of fluid underpressure to said cylinder to cause a rapid movement" 12. A feedingmechanism for a transverselymovable slide comprising a fluid pressurepiston and cylinder operatively connected to move said slide, a manuallyoperable control valve to control the admission of fluid under pressureto said,

cylinder to move slide rapidly in either direction, a feed regulator toproduce a relatively slow feeding movement of the slide when moved inone direction, and a second feed regulator to produce a relatively-slowfeeding movement of the slide when it moves in the opposite direction.

13. A feeding mechanism for a transversely movable slide comprising afluid pressure piston and cylinder operatively connected to move saidslide, a control valve to control the admission of fluid under pressureto said cylinder so as to move the slide rapidly in either direction, ahydraulic feed regulator to produce a relatively slow feeding movementofthe slide during its moveregulator .to produce a relatively slowfeeding movement of the slide during its movement in the oppositedirection.

ment in one direction and a second hydraulic feed 14. A feedingmechanism for a transversely movable slide comprising a fluid pressurepiston and cylinder operatively connected to move said slide, a manuallyoperable control valve to control the admission or fluid under pressureto said cylinder to move the slide rapidly in either direction, ahydraulic feed regulator located adjacent to one end of said cylinderand arranged'to produce a relatively slow feeding movement of the slideduringsits movement in one direction, and a second hydraulic feedregulator located adjacent to the other end of said cylinder, andarranged to produce a relatively slow feeding movement of the slideduring its movement in the opposite direction.

15. A grinding wheel feeding mechanism for a transversely movable slidecomprising a fluid pressure piston and cylinderoperatively connect- 75ed to move said slide, a manually operable control valve to control theadmission of fluid under pressure to said cylinder to move the sliderapidly in either direction, a hydraulic feed regulator located adjacentto one end of said cylinder which is arranged to slow down the rapidapproaching movement to a relatively slow feeding movement, anadjustable positive stop associated therewith to limit the inieedingmovement of said slide, a second hydraulic feed regulator locatedadjacent to the other end of said cylinder and arranged to slow down therapid approaching movement to a relatively slow feeding movement whenthe slide moves in the opposite direction.

16. A grinding wheel feeding mechanism for a transversely movable slidecomprising a fluid pressure piston and cylinder operatively connected tomove said slide in either direction, a manually operable control valveto control the admission of fluid to said cylinder so as to move theslide rapidly in either direction, a hydraulic feed regulator located atone end of said cylinder and arranged to produce a relatively slowfeeding movement after the slide reaches a predetermined position, apositive stop to limit said infeeding movement, a second hydraulic feedregulator located adjacent to the other end of said cylinder andarranged to reduce the rapid approaching movement of said slide to arelatively slow infeeding movement when the slide moves to apredetermined position in the opposite direction, and positive stop tolimit the infeeding movement.

HOWARD W. DUNBAR.

